As DPF regeneration technologies in a diesel engine equipped vehicle, technology for raising an exhaust temperature by post injection (fuel injection using a delayed injection timing for raising a exhaust temperature) into an engine cylinder using an injector and technology for raising a temperature by directly injecting fuel into an exhaust pipe are well known.
However, the former (the post injection into the engine cylinder using the injector) has a problem of dilution of an engine lubricating oil (so-called “oil dilution.”) caused by injection of the fuel into the cylinder.
On the other hand, the latter (direct injection of the fuel into the exhaust pipe) has a difficulty in stably increasing an exhaust temperature due to a fluctuation of a load during travel, and there is a problem that the DPF regeneration can be carried out only when a vehicle is stopped.
As the prior art, technology concerning the DPF regeneration is also suggested (refer to Patent Literature 1 and Patent Literature 2), and technology for detecting stoppage of a vehicle and raising a temperature with the use of an exhaust brake is disclosed, for example (refer to Patent Literature 2).
However, both the prior arts (Patent Literature 1 and Patent Literature 2) do not disclose DPF regeneration technology for stably raising an exhaust temperature during travel.